Capistrano puma:restart 不起作用，但 puma:start 起作用

Question

I am using Capistrano to deploy my Rails 5 app to AWS EC2 instance. When I type:

cap production deploy

Things go smoothly and the deployment is successful. However, the process of restarting puma is not working. The last task I see as:

puma:restart
      01 ~/.rvm/bin/rvm ruby-2.4.0 do bundle exec pumactl -S /home/deploy/myapp/shared/tmp/pids/puma.state -F /home/deploy/myapp/s…
      01 Command restart sent success

However, when I visit my website, I see:

502 Bad Gateway
nginx/1.4.6 (Ubuntu)

Doing cap production puma:status warns me that Puma is not running. Interestingly, cap production puma:start works perfectly with the following echo:

puma:start
      using conf file /home/deploy/myapp/shared/puma.rb
      01 ~/.rvm/bin/rvm ruby-2.4.0 do bundle exec puma -C /home/deploy/myapp/shared/puma.rb --daemon
      01 Puma starting in single mode...
      01
      01 * Version 3.9.1 (ruby 2.4.0-p0), codename: Private Caller
      01
      01 * Min threads: 0, max threads: 8
      01
      01 * Environment: production
      01
      01 * Daemonizing...
      01

I have spent a few hours trying to find out what the issue is. I can work around the issue by doing starting the Puma server everytime I deploy instead of the restart or phased_restart tasks. But what could be causing this? I deployed a similar app 2 weeks back (it was an API only app) and it worked without any issues.

Here is my deploy.rb:

lock "3.8.2"

set :application, "myapp"
set :repo_url, "git@bitbucket.org:myorg/myapp.git"

# set :branch, :master
set :branch, :release
set :deploy_to, '/home/deploy/myapp'
set :pty, true
set :linked_files, %w{config/database.yml config/application.yml}
# set :linked_dirs, %w{bin log tmp/pids tmp/cache tmp/sockets vendor/bundle public/system public/uploads}
set :linked_dirs, %w{log tmp/pids tmp/cache tmp/sockets vendor/bundle public/system public/uploads}

set :keep_releases, 5
set :rvm_type, :user
set :rvm_ruby_version, 'ruby-2.4.0'

set :puma_rackup, -> { File.join(current_path, 'config.ru') }
set :puma_state, "#{shared_path}/tmp/pids/puma.state"
set :puma_pid, "#{shared_path}/tmp/pids/puma.pid"
set :puma_bind, "unix://#{shared_path}/tmp/sockets/puma.sock"
set :puma_conf, "#{shared_path}/puma.rb"
set :puma_access_log, "#{shared_path}/log/puma_error.log"
set :puma_error_log, "#{shared_path}/log/puma_access.log"
set :puma_role, :app
set :puma_env, fetch(:rack_env, fetch(:rails_env, 'production'))
set :puma_threads, [0, 8]
set :puma_workers, 0
set :puma_worker_timeout, nil
set :puma_init_active_record, true
set :puma_preload_app, false

My config/deploy/production.rb:

server 'myapp.com', user: 'deploy', roles: %w{web app db}

My puma.rb:

#!/usr/bin/env puma

directory '/home/deploy/myapp/current'
rackup "/home/deploy/myapp/current/config.ru"
environment 'production'
daemonize true

tag ''

pidfile "/home/deploy/myapp/shared/tmp/pids/puma.pid"
state_path "/home/deploy/myapp/shared/tmp/pids/puma.state"
stdout_redirect '/home/deploy/myapp/shared/log/puma_error.log', '/home/deploy/myapp/shared/log/puma_access.log', true

threads 0,8

bind 'unix:///home/deploy/myapp/shared/tmp/sockets/puma.sock'

workers 0
prune_bundler

on_restart do
  puts 'Refreshing Gemfile'
  ENV["BUNDLE_GEMFILE"] = "/home/deploy/myapp/current/Gemfile"
end

I am really stuck here. Even after hours of research, I cannot find a solution that works!

Answer 1

As pointed out in the comments by Matt, this seems to be a reported bug. I have monkey patched the puma:restart task as a temporary solution until this gets fixed.

I have created /lib/capistrano/tasks/overwrite_restart.rake:

namespace :puma do
  Rake::Task[:restart].clear_actions

  desc "Overwritten puma:restart task"
  task :restart do
    puts "Overwriting puma:restart to ensure that puma is running. Effectively, we are just starting Puma."
    puts "A solution to this should be found."
    invoke 'puma:stop'
    invoke 'puma:start'
  end
end

As an alternative, I guess we could overwrite the :register_hooks method in the capistrano-puma gem, and replace puma:restart with puma:stop and puma:start .

Answer 2

I ran into the problem that Capistrano Puma basic tasks were not showing up (restart, stop, start). This happens because, in Capistrano Puma 5.0, the tasks were moved to the service manager modules,

After

require "capistrano/puma"
install_plugin Capistrano::Puma

be sure to add:

install_plugin Capistrano::Puma::Daemon

Note that this is incompatible with Puma 5+ as daemonization support was removed.

Source: https://github.com/seuros/capistrano-puma/issues/310

or if you use Systemd

install_plugin Capistrano::Puma::Systemd

then all tasks should show up now and Puma should restart after deployment.